The levels of pituitary gonadotrophins (follicle stimulating hormone and luteinizing hormone) activities, the ovarian weight and the ovarian ascorbic acid level were estimated in pregnant and lactating rats. The level of pituitary follicle stimulating hormone activity rose sharply in the second half of gestation, and reached the peak on day 19 of pregnancy, and then dropped abruptly prior to the day of labor. The ovarian weight fluctuated almost coincidentally with the pituitary follicle stimulating hormone activity. The level of pituitary luteinizing hormone activity fluctuated with two peak values. It reached the first peak on day 14 and the second peak on day 19, and dropped abruptly prior to the day of labor. The ovarian ascorbic acid content fluctuated reversely with the fluctuation of pituitary luteinizing hormone activity until day 18. The content continued to decrease until the day of labor. These results suggested that a) the anterior pitutiary maintained its activity during pregnancy; b) three days before the onset of labor, it started to release luteinizing hormone and two days before that, it started to decrease in release of follicle stimulating hormone; and c) pregnancy terminated following decrease of circulating follicle stimulating hormone activity and sharp increase of circulating luteinizing hormone activity.
A homozygous erythrocyte glutathione-peroxidase deficiency was reported of a 9-month-old girl, who showed clinical pictures of non-spherocytic hemolytic anemia since the age of 4 months. Clinical and biochemical findings were: 1) persistent reticulocytosis (6.5-13.5%), 2) an increased susceptibility to Heinz-body formation of erythrocytes, 3) a slight increase of methemoglobin in erythrocytes, 4) a marked decrease in glutathione peroxidase activity in both erythrocytes and cultured leukocytes, 5) a marked decrease in activation of the hexose monophosphate shunt of erythrocytes in the presence of hydrogen peroxide, 6) a slight decrease in linoleic, linolenic and arachidonic acids of phosphatidyl-choline of erythrocytes, and 7) the normal activity of erythrocytes for glucose-6-phosphate dehydrogenase, pyruvate kinase, triose phosphate isomerase, 2, 3-diphosphoglyceromutase, ATP-ase, catalase and lactate production.
Effects of dietary folate deficiency on the fatty acid composition of myelin cerebroside in growing rats were studied. In non-hydroxy fatty acids, an average ratio of 24:1/24:0 was 1.27 in control rats and 0.87 in folate deficient rats, respectively. In hydroxy-fatty acids, a significant decrease in both Ch24:0 and Ch24:1 was observed in folate deficient rats. These results indicate that folio acid may play a certain role in desaturation and/or hydroxylation of long chain fatty acids in the brain of growing rats.
Population kinetic analysis was made for growth fraction and median cell cycle time over 9 days after irradiation of a mouse mammary tumor cell population (FM3A) treated with 500 and 700 R of 60Co gamma-rays, where the growth fraction was estimated from labeling indices determined by the staggered addition method with 3H-thymidine and colchicine, and the median cell cycle time from the rate of c-mitosis accumulation by colchicine as well as the growth fraction. The analysis revealed a modest proliferation of the median cell cycle time of proliferating cells in the gamma-irradiated population. Irrespective of the doses of irradiation, the most remarkable reduction in the growth fraction was noted to occur on the third day of irradiation. The data obtained indicate that the diminution of the rate of increase in total cell number is derived primarily from decrement of the growth fraction and not largely attributable to prolonged cell cycle time, and the decline in the growth fraction is due to departure from the cell cycle and/or death of the cell.
An increase in serum folate levels after an oral load of histidine was observed in all the 18 patients tested. Less increase in serum folate after the load was found in one case of formiminotransferase deficiency, two cases with decreased activity of epidermal histidase, one case of congenital syphilis, and two cases of mental retardation of unknown cause.
A direct effect of methoxamine on the contractile state of heart muscle was determined by examining its effects on isometric peak force (F), maximum velocity of force development (dF/dt) and time to peak force (TPF) in isolated canine trabeculae. Methoxamine at the concentrations over 5×10-5M caused a concentration-dependent depression of F and dF/dt. TPF was slightly shortened at higher concentrations of methoxamine (over 1×10-4M). These results suggest that methoxamine possesses a direct negative inotropic action which is mainly due to a decrease in the intensity of the active state. An increase in F produced by isoproterenol was antagonized by methoxamine at a concentration about 100 times higher than that of isoproterenol, suggesting a weak beta-adrenergic blocking action of methoxamine. This antagonistic action of methoxamine was seen also in the effects of isoproterenol on dF/dt as well as TPF. The effect of methoxamine on the mechanics of muscle contraction is qualitatively similar to, but quantitatively different from that of other beta-adrenergic blockers.
The chemical nature of phospholipids in rat lung tissue and alveolar wash was studied using column chromatographies on silicic acid and DEAE-cellulose and thin-layer chromato-graphy followed by gas chromatography to determine the fatty acid composition of the major phospholipid fractions. It was found that alveolar phospholipids obtained by lung lavage differed from those in lung tissue in several aspects. Predominant phospholipid from both sources was lecithin which composed 68% of alveolar phospholipids and 52% of lung tissue phospholipids. Alveolar lecithin contained much higher disaturated species than lung tissue. Lipids X1, X2 and X3 were found in higher proportions in alveolar wash. The X3 seemed to be identical with cardiolipin from the data of Rf values of intact lipids as well as deacylated products, and elution pattern with DEAE-cellulose. The acidic lipid X2 seemed to be probably phosphatidylglycerol. Lipid Xl could not be identified. The present results suggested that lecithin and the three acidic phospholipids could be secreted more preferentially into alveolar cavity than other lipids, such as neutral lipids, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol and sphingomyelin.
Turnover time of tissue and alveolar lecithins of rat lung was determined according to the decay curve of radioactivity as well as the precursor-product relationship by Zilversmit's equation, from specific activity of lecithin and its subspecies after intravenous injection of 3H-palmitate, 14C-glycerol and 3H-choline. The turnover times of alveolar lecithins were 5.1 hours with 3H-palmitate, 5.6 hours with 14C-glycerol and 14.9 hours with 3H-choline, respectively, from the calculation according to Zilversmit's equation. The turnover times of tissue lecithins were determined as 20.5 hours, 19.8 hours and 67.7 hours, respectively, from their half lives. Certain aspects regarding turnover rate of lecithin in lung tissue as well as its secretion rate into alveolar cavity were discussed using the data reported by other investigators as well as our present data.
The Isolated testicular preparation of rabbit responded to acetylcholine, noradrenaline, adrenaline and isoproterenol with contractions or relaxations. Cholinergic and adrenergic receptor blocking agents revealed the presence of muscarinic receptors, and adrenergic α- and β-receptors in this preparation. Field stimulation with A. C. (3 V/cm, 50 Hz) or DMPP, elicited contractions which are susceptible to bretylium but to neither hexamethonium nor atropine. These results may rather be taken as evidence for the presence of adrenergic innervation to the rabbit testis. The testicular preparation showed slow spontaneous rhythmic contractions. These spontaneous contractions as well as the contractions elicited by field stimulation were entirely abolished by manganese ion. However, these contractions were resistant to TTX, and were little influenced even by removal of the parenchymal tissues from the capsule. These results may imply the possible presence of smooth muscle cells or other contractile tissues resembling smooth muscle cells within the testicular capsule.
The effect of melanization on the tyrosinase and acid phosphatase of melanosomes isolated from Harding-Passey mouse melanomas was studied. Inactivation effect was clearly shown in both tyrosinase activity and acid phosphatase activity to be due to melanization. The melanosomes melanized in vitro and in vivo were treated with deoxycholate, and subjected to sonication and trypsin digestion. No significant tyrosinase activity was released from these melanosomes by such treatment. Therefore, the blocking processes of the active center in tyrosinase are assumed to be very tight and impossible to remove easily. The inactivation process of tyrosinase might be irreversible during melanization of melanosomes. Under the scanning electron microscope melanosomes appear to be covered unevenly by amorpous masses during melanization.
Responses of the isolated human testicular capsule to electrical stimulation and to some autonomic drugs were investigated. The capsule showed marked contractions to acetylcholine, noradrenaline and field stimulation with A. C. The response to acetylcholine was easily abolished by atropine, and the response to noradrenaline was reversed to relaxation after phentolamine. The contrac tion elicited by field stimulation was reduced by bretylium or tetrodotoxin which indicates the presence of adrenergic nerves in the capsule. It is suggested from these data that the human testicular capsule has many pharmacological similarities to that of rabbit.
A trial was made to measure the intratesticular pressure development of dog at sympathetic nerve stimulation. Stimulation of the perivascular nerve running along the spermatic vessels apparently raised the intratesticular pressure. This result may indicate that rise in the intratesticular pressure passibly endows some propelling force to non-motile spermatozoa in the seminiferous tubules of the testis.